Image display surfaces in image display devices such as liquid crystal displays (LCDs) or cathode ray tube display devices (CRTs) are required to reduce the reflection of light applied from an external light source and thus to enhance the visibility of the image. To meet this demand, it is common practice to utilize an optical laminate comprising an anti-dazzling layer or anti-reflection layer provided on a light transparent base material (for example, an anti-reflective laminate) and thus to reduce the reflection of light from an image display surface in the image display device, whereby the visibility of the image is improved.
In an optical laminate comprising layers with a large refractive index difference stacked on top of each other, however, interface reflection and interference fringes often occur at the interface of the mutually superimposed layers. In particular, when black is reproduced on an image display surface in a screen display device, the occurrence of interference fringes is significant, resulting in lowered visibility of the image. Further, it has been pointed out that, in this case, the appearance of the image display surface is deteriorated. In particular, it is said that interference fringes are likely to occur when the refractive index of the light transparent base material and the refractive index of the hardcoat layer are different from each other.
In order to suppress the occurrence of interference fringes, Japanese Patent Laid-Open No. 205563/2003 proposes a method for forming, on a base material, a hardcoat layer using a resin containing a solvent capable of dissolving the base material.
So far as the present inventors know, up to now, there have not been proposed an optical laminate comprising a light transparent base material and a hardcoat layer, formed on the light transparent base material, using two or more resins having a specific molecular weight and containing a functional group(s) and a penetrative solvent, the interface between the light transparent base material and the hardcoat layer having been rendered substantially absent.